/Engine/Plugins/Online/OnlineSubsystem/Source/Public/Interfaces/VoiceInterface.h
Sets the playback priority of a remote talker for the given user. A priority of 0xFFFFFFFF indicates that the player is muted. All other priorities sorted from zero being most important to higher numbers being less important.
0 upon success, an error code otherwise
uint32 SetPlaybackPriority ( uint32 LocalUserNum, const [FUniqueNetId](API\Runtime\CoreOnline\Online\FUniqueNetId) & RemoteTalkerId, uint32 Priority )